>> what i wanted to do and show him how you could be a responsible user of technology without abusing it, without becoming addicted. >> reporter: janell kaufman's message has struck a message with parents, worried about the increasing use of smartphones. more than 50 million iphones are projected to sell this holiday season alone, many to teens just like greg. josh shipp says a set of rules is a must for teen iphone use. >> you couldn't give your kid a car without insurance. so giving them a cell phone or a computer without teaching them how to use it responsibly is irresponsible on the part of the parent. >> reporter: among the 18 conditions, number seven -- >> do not involve yourself in conversations that are hurtful to others. >> reporter: and number 12, a lesson some celebrities could use this year. take note, rihanna. >> do not end or receive pictures of your private parts or anyone else's private parts. >> reporter: he's especially nervous about rule six, which says he's responsible for replacement cost if it falls into the toilet or vanishes into thin air. a legitimate consider